POUR FOAM WITH FLOOR IN OR OUT?

[digitaldav]

What is the best way to pour foam along stringers? Should floor be installed completely, then drill 2" holes about 1 foot apart for air to escape along with access foam?<br />Or just pour the foam along side stringer and hope fills completely under floor then do alot of trimming.

 

[DJ]

Re: POUR FOAM WITH FLOOR IN OR OUT?

digital,<br /><br />Every boat factory I have ever been to poured the foam in before the floor was put down.<br /><br />They have it pretty well calculated as to expansion rates, etc.<br /><br />I don't like the idea of having extra access holes in the floor. Just more areas for problems to arise.

 

[mellowyellow]

Re: POUR FOAM WITH FLOOR IN OR OUT?

agree with JB,<br />u can always cut foam to accomadate floor.<br />the less holes the better!<br />good luck,<br />M.Y.

 

[bhalsdorf]

Re: POUR FOAM WITH FLOOR IN OR OUT?

I poured my foam before installing the floor. You get less air pockets and better filling. The foam can be cut down flush to accomadate the floor quite easily. I also used a piece of scrap plywood covered with a plastic bag so that the foam would not just rise up but would spread out as it expanded. I would put the scrap piece over the top resting on the stringers. It makes the foam rise to the right height then expand outwards to fill the area.

 

[sea wolf]

Re: POUR FOAM WITH FLOOR IN OR OUT?

definately pour before u put the floor down. if it can't escape it may blow out a bulkhead or do damage to the hull.

 

[digitaldav]

Re: POUR FOAM WITH FLOOR IN OR OUT?

Thanks everyone for the help.<br />I did pour before I floored. I also added many packing peanuts to help fill, worked out great.<br />Bill, I used your suggestion and used my precut floor covered with plastic bag to help force the foam out instead of just up. Worked like a charm,<br />thanks again.<br />Next screw the deck down and glass in.<br />Hooray...

 

[Hawkeye1]

Re: POUR FOAM WITH FLOOR IN OR OUT?

Why are you going to screw the floor down? I would epoxy puddy it down with just a couple screws. Those screws could end up working loose and allowing water to seep in and ruin the stringers. Most boat builders glue them down and glass over the hole floor and up the sides 4" or so.

 

[JasonJ]

Re: POUR FOAM WITH FLOOR IN OR OUT?

Hawkeye1, I screwed my floor down with 1 1/2 inch stainless screws every six inches along all six stringers, then glassed the entire floor in. I assume it will be alright, it is certainly strong. I will be deviating from everyone else and hole-sawing holes and pouring the foam in through the holes. I will do this by super-elevating the bow, and pouring through holes every few feet starting at the transom. Once the foam starts to come out the hole, I will place the cut out portion in, and place a brick on top of it. Once cured, I will glass over the holes, and it will be sealed. I had considered foaming with the floor out, but I prefer the thought of how I will be doing it. Either way has its merits. I think foaming with the floor in place will give more structure, and is another bonding agent (in addition to the 5 million screws and glass). Yes, I'll be monitoring to make sure I don't have a blowout.

 

[bhalsdorf]

Re: POUR FOAM WITH FLOOR IN OR OUT?

JasonJ,<br />Just be careful you don't pour too much in the hole at one tme. I have seen hulls bulge out on the bottom using the method you describe. Also have seen a few posts of that happening opn the fiberglassics site. The floor in my boat is rock solid and I poured mine with the floor out. The floorin method does work as long as you sre carefull not to put too much in areas where it does not have the room to expand properly as it can bulge out the hull.

 

[BillP]

Re: POUR FOAM WITH FLOOR IN OR OUT?

Ditto what Bill H says. If you don't do it right the foam can damage the boat. Sometimes it gets trapped and squeezes the wrong place. You may be able to see how this happens by pouring into a paper towel tube and seeing what happens. It may bulge the tube instead of fully exiting the end.<br /><br />I experienced this on a baby donzi floor installation...the aft area behind a center tank expanded more than the front (about 6')and pushed it up with 3 guys standing on it. The volume mix was fairly accurate and done in a single pour. Common logic says it would have squeezed out the front, which was totally open all the way across the hull...but it didn't. <br /><br />Most big(every one I've seen)boat factories spray the foam in and it expands immediately. They continue the application until visually full. <br /><br />Good luck.

 

[JasonJ]

Re: POUR FOAM WITH FLOOR IN OR OUT?

That is why I am doing it in increments. I will be mixing small batches at a time and working my way towards the bow with the bow super elevated. That way I am controlling the expansion.

 

[RogerL.]

Re: POUR FOAM WITH FLOOR IN OR OUT?

I'm looking for an outlet for the foam used for pouring into floor area.

 

[JGREGORY]

Re: POUR FOAM WITH FLOOR IN OR OUT?

ROGER L. I AM ALSO IN THE PROCESS OF REBUILDING A 1976 WELLCRAFT THAT NEEDS A NEW FLOOR. THE BEST PLACE I FOUND FOR EXPANDING FOAM IS AT WWW.SHOPMANINC.COM THEY SEEM TO HAVE EVERYTHING YOU COULD NEED FOR REBUILDING.

 

[JasonJ]

Re: POUR FOAM WITH FLOOR IN OR OUT?

I bought my foam from USComposites.com, took two $44 8 cubic foot kits to get the job done....

 

[JGREGORY]

Re: POUR FOAM WITH FLOOR IN OR OUT?

Roger, Jason's company and the web site I gave you take you to the same place.

 

[JGREGORY]

Re: POUR FOAM WITH FLOOR IN OR OUT?

Jason, How big was your boat I am wondering how much foam I need. The boat is a 1976 wellcraft 165 airslot and the original foam in it was nothing more than 1 length per stringer about the size of a 2 x 4 x 10'. Any help would be great.

 

[bhalsdorf]

Re: POUR FOAM WITH FLOOR IN OR OUT?

I bought my foam from the following link....he ships out right away and prices aren't too bad.<br /><br /> http://www.mertons.com/index.htm

 

[Big Dog]

Re: POUR FOAM WITH FLOOR IN OR OUT?

I also poured the foam in like Jason did. I also screwed the floor down as Jason did but did nut use stailess screws. I used galvanised screws because I was told that the galvanized screws would bite better becuse they were not a slick as stainless.(My .02)<br /><br />I poured the foam in in sections and and alternatited sides to allow the foam to cool down. The heat will make that stuff work faster. I also poured the foam in before totally glassing the floor down just in case I broke the floor out with to much foam.<br /><br />I ended up using 3 2 gallon kits to do a 21 1/2 SeaRay open bow.<br /><br />Make sure you wear gloves and protective clothing as this stuff will not come off your skin, clothes or anything else that it gets on.

 

[BillP]

Re: POUR FOAM WITH FLOOR IN OR OUT?

For what its worth on galvanized screws...I've pulled 25 to 40 yr old hot (hot type are the ones that don't turn out because the rough zinc surface grabs) galvanized screws out of sailboat hulls and they still looked good. These were below the waterline and not glassed over, just plugged and bottom painted. The boats had full time saltwater use. I've recently pulled electro galvanized screws from a trailer boat that were installed 15yrs ago and showed no rust...they were holding ply down and glassed over. Galvanized screws should last at least 50 yrs under glass...maybe even twice that long. Stainless is major overkill for this application but does take ALL the worry of corrosion away...forever.

 

[JasonJ]

Re: POUR FOAM WITH FLOOR IN OR OUT?

Jgregory, my project is 16.5 feet long. You should put in enough foam to displace enough water to keep the boat and its passengers afloat. Water weighs about 65 pounds per cubic feet, but you have to factor the weight of the foam itself, so I used a conservative 62 pounds per cubic foot for my figures. I basically filled all the stringer voids I could, but there is foam sprayed under all surfaces of the upper deck, so that will displace quite a bit of water as well...